Understanding The Anatomy of the Bones of the Foot Understanding The Anatomy of the Bones of the Foot Authored by Hindfoot & Tarsal Bones Over 25 percent of our bones are located in our feet. There are twenty-six bones that make up the complex structure of each foot. The foot is a strong mechanism, and it supports our entire body weight during all upright activities (standing, walking, running, etc). It remains flexible, durable, and resilient under enormous pressure. Structurally, the foot consists of three main parts: the forefoot, midfoot, and hindfoot. Anatomically, the bones of the foot are known as the tarsal bones, metatarsal bones, and phalanges. Let’s break down each category and discuss the importance of each bone. Forefoot: Phalanges and Metatarsal Bones The forefoot comprises fourteen phalanges and five metatarsal bones. One phalanx of each of the five toes connects to one of the five metatarsals. The toes are numbered one through five, starting with the big toe, which is technically known as the hallux.

Some people like to call the fifth toe the “pinky.” The phalanges are referred to as follows: The proximal phalanx is the base of each toe and articulates the metatarsal bone and middle phalanx. The middle phalanx is located under the distal phalanx in the second, third, fourth and fifth toes only. The hallux does not have a middle phalanx. The distal phalanx is found at the end of each toe, forming the tip of the toes. There are five metatarsals in each foot. The metatarsals are the long bones located between the tarsal bones and the phalanges. Each metatarsal has a long shaft with two expanded ends called the base and the head. They form part of the foot’s arch and serve both as a major shock absorber and a weight-transfer mechanism. They are connected to the forefoot and midfoot by muscles, tendons, and a special ligament known as the plantar fascia. The metatarsals are not named individually; rather, they are numbered first through fifth, starting with the big toe.

Here is a quick description of each of the metatarsal bones: The first metatarsal bone is the shortest and thickest. The second metatarsal bone is the longest and is firmly held between the first and third cuneiform bones. This bone is most susceptible to injury. The third metatarsal bone is in the middle and articulates the third cuneiform, as well as the second and fourth metatarsal bones. The fourth metatarsal bone is smaller than the third, but like the third it also articulates the surrounding metatarsals (the third and fifth), and also articulates the cuboid. The fifth metatarsal bone articulates the cuboid and the fourth metatarsal. Jones fractures and stress fractures are common injuries to this bone. There are also two tiny bones located under the hallux (big toe) called sesamoid bones. Sesamoid bones develop within the tendon of a muscle to protect the tendon from wear and tear at the point where it passes over the end of the metatarsal bone. They bear the weight of the body when the toe pushes off in walking or running.

Though it is less common, sesamoid bones can be found elsewhere in the foot within other flexor tendons of the toes. Midfoot: Lesser Tarsal Bones The five bones that make up the midfoot are collectively known as the lesser tarsal bones. They act as an intermediary to transfer weight from the hindfoot to the forefoot with each footstep. These bones, along with the joints and ligaments that connect them, make up most of what we would consider the arch of the foot. They include: The navicular bone is boat-shaped and located in the middle of the foot. It articulates with the talus and the three cuneiform bones. The cuboid bone is shaped like a cube and is the last of the seven tarsal bones, articulating with the fourth and fifth metatarsal bones, calcaneus, and navicular bones. There are three cuneiform bones in all: medial, intermediate, and lateral. They are located in the midfoot region, articulating with the corresponding metatarsal bones and navicular bone.

Hindfoot: Greater Tarsal bones The hindfoot connects the foot to the leg at the ankle joint, and comprises two large bones called the talus and calcaneus. These bones articulate with each other through the subtalar joint, and also link the hindfoot to the midfoot through the mid-tarsal joint. Here is a brief description of each of the tarsal bones: The talus connects the hindfoot to the two leg bones (the tibia and fibula) to form the ankle joint, which acts as a hinge to allow the foot to move up and down. It also links the hindfoot to the midfoot through the navicular bone to form one part of the mid-tarsal joint. From below, the talus meets up with the calcaneus to form the subtalar joint, which allows the foot to move from side to side. The calcaneus is also known as the heel bone, and it is the largest bone in the foot. It connects with the talus from above to form the subtalar joint. It also meets up with the cuboid bone to form the rest of the midtarsal joint.

This joint allows some motion between the hindfoot and midfoot that gives the foot some flexibility Medical References: H.F. Fullmann "Atlas of Anatomy" (Tandem Verlag GmbH, 2009) 100-101 Professor P. Abrahams "A Complete Guide to How the Body Works, The Atlas of the Human Body" (Amber Books, 2009) 222-224 Taber's Cyclopedic Medical Dictionary, 21 edition (F.A. Davis Company, 2005) 893 This page was last updated on October 2nd, 2015 How To Maintain & Improve Your Foot Health A Complete Guide To The Anatomy Of The Foot Foot Anatomy - Podiatrist San Angelo, TX Patient Education Foot Anatomy A marvel of bioengineering, the human foot combines the mechanical complexity of a Swiss watch with the structural strength of a cantilever bridge. The ankle, it serves as foundation, shock absorber and propulsion engine.

The foot can sustain enormous pressure - several tons over the course of a one-mile run, for example - and still provide the combination of flexibility and resiliency needed to support delicate and demanding ballet steps. The foot and ankle contain: 26 bones; 33 joints; more than 100 muscles, tendons (fibrous tissues that connect muscles to bones) and ligaments (fibrous tissues connecting bones to other bones); and a vast network of blood vessels, nerves, skin and soft tissue. Together, the feet contain one-quarter of the bones in the human body. All of these components work together in unison to provide the body with support, balance and mobility. A structural flaw or malfunction in any one part can result in the development of problems elsewhere in the body. Conversely, abnormalities in other parts of the body ultimately can lead to problems in the feet. Parts of the Foot Structurally, the foot has three main parts; the forefoot, the midfoot, and the rearfoot. The forefoot is composed of the five toes, collectively called phalanges, and their connecting long bones, the metatarsals. Each toe, or phalanx, is made up of several small bones.

The big toe, also called the hallux, has two phalanges and one joint (interphalangeal joint); it also features two tiny, round sesamoid bones that enable it to move up and down. The other four toes each have three bones and two joints. The phalanges are connected to the metatarsals by five metatarsal phalangeal joints at the ball of the foot. Collectively, the forefoot bears half the body's weight and balances pressure on the ball of the foot. The midfoot, featuring five irregularly shaped tarsal bones, forms the foot's characteristic arch and serves as a shock absorber. The bones of the midfoot are connected to the forefoot and the rearfoot by muscles and the plantar fascia or arch ligament. The rearfoot, composed of three joints, links the midfoot to the ankle or talus. The top of the talus is connected to the two long bones of the lower leg, the tibia and fibula, forming a hinge that allows the foot to move up and down. The heel bone or calcaneus, is the largest bone of the foot.

It joins the talus to form the subtalar joint, which enables the foot to rotate at the ankle. Its bottom is cushioned with a layer of fat. Supporting this complex of bones and joints is a network of muscles, tendons, and ligaments. There are some 20 muscles in the foot. They give the foot its shape by holding the bones in position, and expand and contract to impart movement to the bones and joints. The main muscles of the foot are: Ankle and Foot Home > Skeletal System > Bones of the Leg and Foot > Ankle and Foot Ankle and Foot The bones of the ankle and foot form the most distal region of the lower limb in the appendicular skeleton. These bones are responsible for the propulsion, balance, and support of the body’s weight through many diverse activities, such as standing, walking, running, and jumping. The ankle joint is formed by the union of the lower leg bones – the tibia and fibula – and the talus bone (one of a group of bones collectively known as the tarsus, located in the foot). Together, these three bones form a tight synovial hinge joint that permits the plantarflexion and dorsiflexion of the foot....

Move up/down/left/right: Click compass arrows Rotate image: Click and drag in any direction, anywhere in the frame Identify objects: Click on them in the image 2D Interactive 3D Rotate & Zoom Change Anatomical System Ankle and Foot, Posterior (Back) Full Ankle and Foot Description [Continued from above] . . . Plantarflexion is the movement that describes the pointing of the foot toward the ground, as in standing on one’s tiptoes. Dorsiflexion is the opposite of plantarflexion and involves the movement of the foot away from the ground, as in pulling the toes up and walking on one’s heels. The medial malleolus of the tibia and the lateral malleolus of the fibula form a cup surrounding the rounded tarsus to prevent lateral movement at the ankle joint. The fibula is united to the bones of the foot on the lateral side of the ankle by the anterior and posterior talofibular ligaments and the calcaneofibular ligament. On the medial side, the wide deltoid ligament binds the tibia to the tarsal bones of the foot.

All of these ligaments work together to limit extreme movements and dislocations of the ankle joint while providing slight lateral flexibility that helps the body walk on uneven surfaces and maintain its balance. Twenty-six small bones of the foot provide the strength and flexibility necessary for bipedal locomotion. The seven tarsal bones form the posterior portion of the foot nearest to the heel. Each tarsal bone is a short bone with many flat facets that allow the tarsals to glide past one another. This gliding motion provides lateral mobility to the foot below the level of the ankle joint and allows the foot to bend to adjust the body’s balance. Anterior to the tarsals are the five long metatarsal bones of the foot and the fourteen phalanges of the toes. The metatarsals, phalanges, and tarsals form the longitudinal and transverse arches of the foot to divide the body’s weight across the entire foot and act as a spring to absorb and release the force of the body’s weight on the ground. These bones also act as a lever to increase the strength of the muscles acting on the ankle joint, allowing the body to easily lift its entire weight up on the balls of the foot and the toes.

This leverage is essential to rapid locomotion and jumping as it greatly increases the strength and speed of the legs. Many different ligaments hold the bones of the foot firmly together while providing flexibility to the bones. Amongst the tarsal bones, the plantar calcaneonavicular ligament joins the navicular bone to the calcaneus (heel bone), while the plantar cuboideonavicular ligament joins the navicular bone to the cuboid bone. The dorsal and plantar tarsometatarsal ligaments bind the tarsal and metatarsal bones together, support the arches of the foot, and strengthen overall structure of the foot. In the anterior of the foot, the plantar metatarsal ligaments bind the instep across the sole of the foot. Prepared by Tim Taylor, Anatomy and Physiology Instructor Foot Bones | Anatomy of Foot in the Human Body| Learn Bones distal phalanges (5 × 2) Tarsal / Ankle Bones The tarsal bones are a series of bones that make up the region known as the tarsus, or more commonly known as the ankle.

Calcaneus (Heel Bone) Click to Enlarge The calcaneus bone, also known as the heel bone, is the largest bone of the tarsal or ankle region. The calcaneus also constitutes the region known as the heel. This bone is very important in movement of the foot and support of the body. Additionally, the calcaneus consists of important structures, such as the Achilles tendon, tarsal sinus, and the tuber calcanei. Talus Click to Enlarge The talus bone, also known as the astragalus, is an irregularly shaped bone of the tarsal or ankle region. This is the second largest of the ankle bones and forms part of the ankle joint. The talus functions in allowing motion of the foot and transfers the body's weight to the foot. Additionally, the talus is divided into three regions: the head, neck, and body. Cuboid Click to Enlarge The cuboid bone is one of the several bones found in the tarsal or ankle region. This bone is found in each ankle and thus contributes two bones to the human skeleton. The function of the cuboid is support of the body's weight, locomotion, and maintaining lateral foot stability.

Additionally, the cuboid bone forms part of many joints in the foot, such as the tarsometatarsal and calcaneocuboid joints. Navicular Click to Enlarge The navicular bone is one of the bones of the tarsal or ankle region. This bone is found in each ankle and contributes two bones to the human body skeleton. The navicular is a relatively small bone that plays a function in locomotion and body support. It touches five other bones: the three cuneiform bones, the talus bone, and the cuboid bone. Additionally, the navicular resembles a boat due to its concavity. Lateral Cuneiform Click to Enlarge The lateral cuneiform bones are two bones of the tarsal or ankle regions in the human skeleton. The lateral cuneiform is a wedge shaped bone located in between the intermediate cuneiform and cuboid bones. Like the other tarsal bones, the lateral cuneiform plays a role in motion and support. Furthermore, the lateral cuneiform is also known as the third cuneiform or external cuneiform. Intermediate Cuneiform Click to Enlarge The intermediate cuneiform bone is located in the ankle region of the skeleton.

This bone is found in each tarsus / ankle and thus contributes two bones to the human body skeleton. The intermediate cuneiform is wedge shaped and is also known as the second cuneiform bone or middle cuneiform bone. The bone plays a role in movement and support of the body. Medial Cuneiform Click to Enlarge The medial cuneiform, also known as the first cuneiform, is a bone found in the tarsus or ankle region. The medial cuneiform is found in each ankle and thus two medial cuneiform bones are found in the entire human skeleton. Like other tarsal bones, this bone plays a role in motion and support of the body. Additionally, the medial cuneiform touches four other bones: the intermediate cuneiform bone, the navicular, and two metatarsal bones. Metatarsal Bones Metatarsal Bones Each foot consists of five metacarpal bones and thus the entire human skeleton consists of ten metatarsal bones. The metatarsal bones are located between the tarsus and the phalanges (toes). The metatarsal bones' primary functions include foot motion, body support, and providing the shape of the foot.

(Diagram of the metatarsal bones is shown at the top of the page). Phalanges The Phalanges consist of three sections. The proximal phalanges, the intermediate phalanges, and the distal phalanges. Collectively, these bones make up the structure known as the toes. (Diagram of the phalanges is shown at the top of the page). Proximal Phalanges The proximal phalanges are found at the base of the toes, closest to the tarsus. These bones are longer than the play an important role in movement of the foot. Intermediate Phalanges The intermediate phalanges are found in between the proximal phalanges and distal phalanges. There are four intermediate phalanges found on each foot, the only toes that lacks the intermediate phalanges are the thumbs. Like the distal phalanges, the intermediate phalanges plays an important role in motion of the foot. Distal Phalanges The distal phalanges are a series of bones found at the tip of the foot, following the intermediate phalanges.

The distal phalanges consists of five bones per foot and thus contribute a total of ten bones to the human skeleton. These bones play an important role in movement of the foot. The anatomy of Foot Bones. Skeletal System – Labeled Diagrams of the Human Skeleton Pectoral (shoulder) girdle Skull The skull is composed of 22 bones that are fused together except for the mandible. These 21 fused bones are separate in children to allow the skull and brain to grow, but fuse to give added strength and protection as an adult. The mandible remains as a movable jaw bone and forms the only movable joint in the skull with the temporal bone . The bones of the superior portion of the skull are known as the cranium and protect the brain from damage. The bones of the inferior and anterior portion of the skull are known as facial bones and support the eyes, nose, and mouth. Hyoid and Auditory Ossicles The hyoid is a small, U-shaped bone found just inferior to the mandible. The hyoid is the only bone in the body that does not form a joint with any other bone—it is a floating bone.

The hyoid’s function is to help hold the trachea open and to form a bony connection for the tongue muscles . The malleus, incus, and stapes—known collectively as the auditory ossicles —are the smallest bones in the body. Found in a small cavity inside of the temporal bone, they serve to transmit and amplify sound from the eardrum to the inner ear. Vertebrae Twenty-six vertebrae form the vertebral column of the human body. They are named by region: Cervical (neck) - 7 vertebrae Sacrum - 1 vertebra Coccyx (tailbone) - 1 vertebra With the exception of the singular sacrum and coccyx, each vertebra is named for the first letter of its region and its position along the superior-inferior axis. For example, the most superior thoracic vertebra is called T1 and the most inferior is called T12. Ribs and Sternum The sternum, or breastbone, is a thin, knife-shaped bone located along the midline of the anterior side of the thoracic region of the skeleton . The sternum connects to the ribs by thin bands of cartilage called the costal cartilage.

There are 12 pairs of ribs that together with the sternum form the ribcage of the thoracic region. The first seven ribs are known as “true ribs” because they connect the thoracic vertebrae directly to the sternum through their own band of costal cartilage. Ribs 8, 9, and 10 all connect to the sternum through cartilage that is connected to the cartilage of the seventh rib, so we consider these to be “false ribs.” Ribs 11 and 12 are also false ribs, but are also considered to be “floating ribs” because they do not have any cartilage attachment to the sternum at all. Pectoral Girdle and Upper Limb The pectoral girdle connects the upper limb (arm) bones to the axial skeleton and consists of the left and right clavicles and left and right scapulae. The humerus is the bone of the upper arm. It forms the ball and socket joint of the shoulder with the scapula and forms the elbow joint with the lower arm bones. The radius and ulna are the two bones of the forearm.

The ulna is on the medial side of the forearm and forms a hinge joint with the humerus at the elbow. The radius allows the forearm and hand to turn over at the wrist joint. The lower arm bones form the wrist joint with the carpals, a group of eight small bones that give added flexibility to the wrist. The carpals are connected to the five metacarpals that form the bones of the hand and connect to each of the fingers. Each finger has three bones known as phalanges, except for the thumb, which only has two phalanges. Pelvic Girdle and Lower Limb Formed by the left and right hip bones, the pelvic girdle connects the lower limb (leg) bones to the axial skeleton. The femur is the largest bone in the body and the only bone of the thigh (femoral) region. The femur forms the ball and socket hip joint with the hip bone and forms the knee joint with the tibia and patella. Commonly called the kneecap, the patella is special because it is one of the few bones that are not present at birth. The patella forms in early childhood to support the knee for walking and crawling.

The tibia and fibula are the bones of the lower leg. The tibia is much larger than the fibula and bears almost all of the body’s weight. The fibula is mainly a muscle attachment point and is used to help maintain balance. The tibia and fibula form the ankle joint with the talus, one of the seven tarsal bones in the foot . The tarsals are a group of seven small bones that form the posterior end of the foot and heel. The tarsals form joints with the five long metatarsals of the foot. Then each of the metatarsals forms a joint with one of the set of phalanges in the toes. Each toe has three phalanges, except for the big toe, which only has two phalanges. Microscopic Structure of Bones The skeleton makes up about 30-40% of an adult’s body mass. The skeleton’s mass is made up of nonliving bone matrix and many tiny bone cells. Roughly half of the bone matrix’s mass is water , while the other half is collagen protein and solid crystals of calcium carbonate and calcium phosphate. Living bone cells are found on the edges of bones and in small cavities inside of the bone matrix.

Although these cells make up very little of the total bone mass, they have several very important roles in the functions of the skeletal system. The bone cells allow bones to: Grow and develop Be repaired following an injury or daily wear Be broken down to release their stored minerals Types of Bones All of the bones of the body can be broken down into five types: long, short, flat, irregular, and sesamoid. Long. Long bones are longer than they are wide and are the major bones of the limbs. Long bones grow more than the other classes of bone throughout childhood and so are responsible for the bulk of our height as adults. A hollow medullary cavity is found in the center of long bones and serves as a storage area for bone marrow. Examples of long bones include the femur, tibia, fibula, metatarsals, and phalanges. Short. Short bones are about as long as they are wide and are often cubed or round in shape. The carpal bones of the wrist and the tarsal bones of the foot are examples of short bones. Flat. Flat bones vary greatly in size and shape, but have the common feature of being very thin in one direction.

Because they are thin, flat bones do not have a medullary cavity like the long bones. The frontal, parietal, and occipital bones of the cranium—along with the ribs and hip bones—are all examples of flat bones. Irregular. Irregular bones have a shape that does not fit the pattern of the long, short, or flat bones. The vertebrae, sacrum, and coccyx of the spine—as well as the sphenoid, ethmoid, and zygomatic bones of the skull—are all irregular bones. Sesamoid. The sesamoid bones are formed after birth inside of tendons that run across joints. Sesamoid bones grow to protect the tendon from stresses and strains at the joint and can help to give a mechanical advantage to muscles pulling on the tendon. The patella and the pisiform bone of the carpals are the only sesamoid bones that are counted as part of the 206 bones of the body. Other sesamoid bones can form in the joints of the hands and feet, but are not present in all people. Parts of Bones The long bones of the body contain many distinct regions due to the way in which they develop.

At birth, each long bone is made of three individual bones separated by hyaline cartilage. Each end bone is called an epiphysis (epi = on; physis = to grow) while the middle bone is called a diaphysis (dia = passing through). The epiphyses and diaphysis grow towards one another and eventually fuse into one bone. The region of growth and eventual fusion in between the epiphysis and diaphysis is called the metaphysis (meta = after). Once the long bone parts have fused together, the only hyaline cartilage left in the bone is found as articular cartilage on the ends of the bone that form joints with other bones. The articular cartilage acts as a shock absorber and gliding surface between the bones to facilitate movement at the joint. Looking at a bone in cross section, there are several distinct layered regions that make up a bone. The outside of a bone is covered in a thin layer of dense irregular connective tissue called the periosteum. The periosteum contains many strong collagen fibers that are used to firmly anchor tendons and muscles to the bone for movement.

Stem cells and osteoblast cells in the periosteum are involved in the growth and repair of the outside of the bone due to stress and injury. Blood vessels present in the periosteum provide energy to the cells on the surface of the bone and penetrate into the bone itself to nourish the cells inside of the bone. The periosteum also contains nervous tissue and many nerve endings to give bone its sensitivity to pain when injured. Deep to the periosteum is the compact bone that makes up the hard, mineralized portion of the bone. Compact bone is made of a matrix of hard mineral salts reinforced with tough collagen fibers. Many tiny cells called osteocytes live in small spaces in the matrix and help to maintain the strength and integrity of the compact bone. Deep to the compact bone layer is a region of spongy bone where the bone tissue grows in thin columns called trabeculae with spaces for red bone marrow in between. The trabeculae grow in a specific pattern to resist outside stresses with the least amount of mass possible, keeping bones light but strong. Long bones have a spongy bone on their ends but have a hollow medullary cavity in the middle of the diaphysis.

The medullary cavity contains red bone marrow during childhood, eventually turning into yellow bone marrow after puberty. Articulations An articulation, or joint, is a point of contact between bones, between a bone and cartilage, or between a bone and a tooth. Synovial joints are the most common type of articulation and feature a small gap between the bones. This gap allows a free range of motion and space for synovial fluid to lubricate the joint. Fibrous joints exist where bones are very tightly joined and offer little to no movement between the bones. Fibrous joints also hold teeth in their bony sockets. Finally, cartilaginous joints are formed where bone meets cartilage or where there is a layer of cartilage between two bones. These joints provide a small amount of flexibility in the joint due to the gel-like consistency of cartilage. Skeletal System Physiology Support and Protection The skeletal system’s primary function is to form a solid framework that supports and protects the body's organs and anchors the skeletal muscles. The bones of the axial skeleton act as a hard shell to protect the internal organs—such as the brain and the heart —from damage caused by external forces.

The bones of the appendicular skeleton provide support and flexibility at the joints and anchor the muscles that move the limbs. Movement The bones of the skeletal system act as attachment points for the skeletal muscles of the body. Almost every skeletal muscle works by pulling two or more bones either closer together or further apart. Joints act as pivot points for the movement of the bones. The regions of each bone where muscles attach to the bone grow larger and stronger to support the additional force of the muscle. In addition, the overall mass and thickness of a bone increase when it is under a lot of stress from lifting weights or supporting body weight. Hematopoiesis Red bone marrow produces red and white blood cells in a process known as hematopoiesis. Red bone marrow is found in the hollow space inside of bones known as the medullary cavity . Children tend to have more red bone marrow compared to their body size than adults do, due to their body’s constant growth and development. The amount of red bone marrow drops off at the end of puberty, replaced by yellow bone marrow. Storage The skeletal system stores many different types of essential substances to facilitate growth and repair of the body.

The skeletal system’s cell matrix acts as our calcium bank by storing and releasing calcium ions into the blood as needed. Proper levels of calcium ions in the blood are essential to the proper function of the nervous and muscular systems. Bone cells also release osteocalcin, a hormone that helps regulate blood sugar and fat deposition. The yellow bone marrow inside of our hollow long bones is used to store energy in the form of lipids. Finally, red bone marrow stores some iron in the form of the molecule ferritin and uses this iron to form hemoglobin in red blood cells. Growth and Development The skeleton begins to form early in fetal development as a flexible skeleton made of hyaline cartilage and dense irregular fibrous connective tissue. These tissues act as a soft, growing framework and placeholder for the bony skeleton that will replace them. As development progresses, blood vessels begin to grow into the soft fetal skeleton, bringing stem cells and nutrients for bone growth. Osseous tissue slowly replaces the cartilage and fibrous tissue in a process called calcification. The calcified areas spread out from their blood vessels replacing the old tissues until they reach the border of another bony area.

At birth, the skeleton of a newborn has more than 300 bones; as a person ages, these bones grow together and fuse into larger bones, leaving adults with only 206 bones. Flat bones follow the process of intramembranous ossification where the young bones grow from a primary ossification center in fibrous membranes and leave a small region of fibrous tissue in between each other. In the skull these soft spots are known as fontanels, and give the skull flexibility and room for the bones to grow. Bone slowly replaces the fontanels until the individual bones of the skull fuse together to form a rigid adult skull. Long bones follow the process of endochondral ossification where the diaphysis grows inside of cartilage from a primary ossification center until it forms most of the bone. The epiphyses then grow from secondary ossification centers on the ends of the bone. A small band of hyaline cartilage remains in between the bones as a growth plate. As we grow through childhood, the growth plates grow under the influence of growth and sex hormones, slowly separating the bones. At the same time the bones grow larger by growing back into the growth plates.

This process continues until the end of puberty, when the growth plate stops growing and the bones fuse permanently into a single bone. The vast difference in height and limb length between birth and adulthood are mainly the result of endochondral ossification in the long bones. Prepared by Tim Taylor, Anatomy and Physiology Instructor Foot & Ankle Anatomy - Foot Anatomy - HealthCommunities.com Foot & Ankle Anatomy Print Anatomy of the Foot and Ankle The human foot combines mechanical complexity and structural strength. The ankle serves as foundation, shock absorber and propulsion engine. The foot can sustain enormous pressure (several tons over the course of a one-mile run) and provides flexibility and resiliency. The foot and ankle contain: 26 bones (One-quarter of the bones in the human body are in the feet.); 33 joints; more than 100 muscles, tendons and ligaments (Tendons are fibrous tissues that connect muscles to bones and ligaments are fibrous tissues that connect bones to other bones.); and a network of blood vessels, nerves, skin, and soft tissue. These components work together to provide the body with support, balance, and mobility.

A structural flaw or malfunction in any one part can result in the development of problems elsewhere in the body (such as back pain ). Abnormalities in other parts of the body can lead to problems in the feet. Parts of the Foot Structurally, the foot has three main parts: the forefoot, the midfoot, and the hindfoot. Top View of Foot Bones Side View of Foot Bones Click on the images to view a larger version. The forefoot is composed of the five toes (called phalanges) and their connecting long bones (metatarsals). Each toe (phalanx) is made up of several small bones. The big toe (also known as the hallux) has two phalanx bones—distal and proximal. It has one joint, called the interphalangeal joint. The big toe articulates with the head of the first metatarsal and is called the first metatarsophalangeal joint (MTPJ for short). Underneath the first metatarsal head are two tiny, round bones called sesamoids. The other four toes each have three bones and two joints.

The phalanges are connected to the metatarsals by five metatarsal phalangeal joints at the ball of the foot. The forefoot bears half the body's weight and balances pressure on the ball of the foot. The midfoot has five irregularly shaped tarsal bones, forms the foot's arch, and serves as a shock absorber. The bones of the midfoot are connected to the forefoot and the hindfoot by muscles and the plantar fascia (arch ligament). The hindfoot is composed of three joints and links the midfoot to the ankle (talus). The top of the talus is connected to the two long bones of the lower leg (tibia and fibula), forming a hinge that allows the foot to move up and down. The heel bone (calcaneus) is the largest bone in the foot. It joins the talus to form the subtalar joint. The bottom of the heel bone is cushioned by a layer of fat. Publication Review By: John J. Swierzewski, D.P.M.

Published: 30 Dec 1999 Bones of the Foot - Tarsals - Metatarsals - Phalanges - TeachMeAnatomy The human foot is a very complex and highly developed structure. The bones of the foot provide mechanical support for the soft tissues, helping the foot withstand the weight of the body. The bones of the foot can be divided into three categories: Tarsals – A set of seven irregularly shaped bones. They are situated proximally in the foot, in the ankle area. Metatarsals – These bones connect the phalanges to the tarsals. There are five in number – one for each digit. Phalanges – The bones of the toes. Each toe has three phalanges – a proximal, intermediate and distal (except the big toe, which only has two phalanges). Fig 1.0 – Overview of the bones of the human foot. Tarsals The tarsal bones of the foot are organised into three rows; proximal, intermediate and distal. Proximal Group The proximal tarsal bones are the talus and the calcaneus. They form the bony framework around the proximal ankle and heel area.

The talus is the most superior of the tarsal bones. It has three articulations: Superiorly: Ankle joint – between the talus and the bones of the leg (the tibia and fibula). Inferiorly: Subtalar joint – between the talus and calcaneus. Anteriorly: Talonavicular joint – between the talus and the navicular. The main function of the talus is to transmit forces from the tibia to the heel bone (known as the calcaneus). Whilst numerous ligaments attach to the talus, it is not a site of muscle attachment or origin. Fig 1.1 – The tarsal bones of the foot. The calcaneus lies underneath the talus, and has two articulations: Superiorly: Subtalar joint – between the calcaneus and the talus. Anteriorly: Calcaneocuboid joint – between the calcaneus and the cuboid. It is thick and sturdy, acting to transmit forces from the talus to the ground. The posterior aspect of the calcaneus is marked by calcaneal tuberosity, to which the Achilles tendon attaches.

Intermediate Group The intermediate row of tarsal bones contains one bone, the navicular (given its name because it is shaped like a boat). It articulates with the talus posteriorly, the cuneiform bones anteriorly, and the cuboid bone laterally. On the plantar surface of the navicular, there is a tuberosity for the attachment of the tibialis posterior tendon. Distal Group In the distal row, there are four tarsal bones – the cuboid and the three cuneiforms. These bones articulate with the metatarsals of the foot. The cuboid is the most lateral bone in the distal row, articulating with the calcaneus posteriorly, and two metatarsals anteriorly. As the name suggests, it is shaped like a cube. The inferior surface of the cuboid is marked by a groove for the fibularis longus muscle. The three cuneiforms (lateral, intermediate and medial) are wedge shaped bones. They articulate with the navicular posteriorly, and the metatarsals anteriorly. The shape of the bones helps form a transverse arch across the foot.

Clinical Relevance: Fractures of the Talus and Calcaneus The talus and the calcaneus sit in the proximal part of the foot and ankle, and are involved in transmitting forces from the body to the ground. They are the most frequently fractured of all the tarsal bones. Talus Talar fractures occur in two places – the neck of the talus, or the body: Neck fractures are caused by excessive dorsiflexion of the foot. The neck of the talus is pushed against the tibia. In this type of fracture, the blood supply to the talus may be disturbed, leading to avascular necrosis of the bone. Body fractures usually occur from jumping from a height. In any fracture of the talus, the malleoli of the leg bones act to hold the fragments together, so there is little displacement of the fracture pieces. By Jojo (Own work) [CC-BY-SA-3.0], via Wikimedia Commons Fig 1.2 – X-ray of a calcaneal fracture. Calcaneus The calcaneus is often fractured in a ‘crush‘ type injury.

The most common mechanism of damage is falling onto the heel from a height – the talus is driven into the calcaneus. The bone can break into several pieces – known as a comminuted fracture. Upon x-ray, the calcaneus will appear shorter and wider. Even after treatment, a calcaneal fracture can cause further problems. The sub-talar joint is usually disrupted, causing the joint to become arthritic. The patient will experience pain upon inversion and eversion – which can make walking on uneven ground particularly painful. Metatarsals The metatarsals are located in the midfoot, between the tarsals and phalanges. They are numbered I-V (medial to lateral). Each metatarsal has a similar structure. They consist of a distal head and proximal base, which are joined by a shaft of bone. They have three or four articulations: Proximally: Tarsometatarsal joint – between the metatarsal bases and the cuneiforms or cuboid bones. Laterally: Intermetatarsal joint(s) – between the metatarsal and the adjacent metatarsals.

Distally: Metatarsophalangeal joint – between the metatarsal head and the proximal phalanx. Clinical Relevance: Fractures of the Metatarsal Bones Metatarsal fractures can occur by three mechanisms. The most common method of fracture is a direct blow to the foot – usually from a heavy object dropping onto the foot. Another type of metatarsal injury is a stress fracture, an incomplete fracture caused by repeated stress to the bone. It is common in athletes, and occurs most frequently to metatarsals II, III and IV. The metatarsals can also be fractured by excessive inversion of the foot. If the foot is violently inverted, the fibularis brevis muscle can avulse (‘tear off’) the base of metatarsal V. Phalanges The phalanges are the bones of the toes. Most toes have three phalanges – proximal, intermediate and distal. The great toe only has proximal and distal phalanges. Each phalanx consists of a body, a proximal extremity and a distal extremity.

Human Appendicular Skeleton About Watch and Favorite Watch Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made. Favorite Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students. Human Appendicular Skeleton The appendicular skeleton supports the attachment and functions of the upper and lower limbs of the human body. Learning Objective Describe the bones and functions of the human appendicular skeleton Key Points The human appendicular skeleton is composed of the bones of the upper limbs, the lower limbs, the pectoral girdle, and the pelvic girdle. The pectoral girdle acts as the point of attachment of the upper limbs to the body. The upper limb consists of the arm, the forearm, and the wrist and hand. The pelvic girdle is responsible for bearing the weight of the body and is responsible for locomotion; it is also responsible for attaching the lower limbs to the body. The lower limbs, including the thighs, legs, and feet, support the entire weight of the body and absorb the resulting forces from locomotion.

Terms Full Text Human Appendicular Skeleton The human appendicular skeleton is composed of the bones of the upper limbs (which function to grasp and manipulate objects) and the lower limbs (which permit locomotion). It also includes the pectoral (or shoulder) girdle and the pelvic girdle, which attach the upper and lower limbs to the body, respectively . The appendicular skeleton is composed of the bones of the pectoral limbs (arm, forearm, hand), the pelvic limbs (thigh, leg, foot), the pectoral girdle, and the pelvic girdle. The Pectoral Girdle The pectoral girdle bones, providing the points of attachment of the upper limbs to the axial skeleton , consists of the clavicle (or collarbone) in the anterior, as well as the scapula (or shoulder blades) in the posterior . The clavicles, S-shaped bones that position the arms on the body, lie horizontally across the front of the thorax (chest) just above the first rib. (a) The pectoral girdle in primates consists of the clavicles and scapulae.

(b) The posterior view reveals the spine of the scapula to which muscle attaches. The scapulae are flat, triangular bones that are located at the back of the pectoral girdle. They support the muscles crossing the shoulder joint. The spine runs across the back of the scapula; it is a good example of a bony protrusion that facilitates a broad area of attachment for muscles to bone. The Upper Limbs The upper limbs contain 30 bones in three regions: the arm (shoulder to elbow), the forearm (ulna and radius), and the wrist and hand . The humerus is the largest and longest bone of the upper limb and the only bone of the arm. It articulates (joins) with the scapula at the shoulder and with the forearm at the elbow. The forearm, extending from the elbow to the wrist, consists of two bones: the ulna and the radius. The radius, located along the lateral (thumb) side of the forearm, articulates with the humerus at the elbow. The ulna, located on the medial aspect (pinky-finger side) of the forearm, is longer than the radius. It articulates with the humerus at the elbow.

The radius and ulna also articulate with the carpal bones and with each other, which in vertebrates enables a variable degree of rotation of the carpus with respect to the long axis of the limb. The hand includes the eight bones of the carpus (wrist), the five bones of the metacarpus (palm), and the 14 bones of the phalanges (digits). Each digit consists of three phalanges, except for the thumb, which, when present, has only two. The upper limb consists of the humerus of the upper arm, the radius and ulna of the forearm, eight bones of the carpus, five bones of the metacarpus, and 14 bones of the phalanges. The Pelvic Girdle The pelvic girdle attaches to the lower limbs of the axial skeleton and is responsible for bearing the weight of the body and for locomotion. It is securely attached to the axial skeleton by strong ligaments. It also has deep sockets with robust ligaments to securely attach the femur to the body. The pelvic girdle is further strengthened by two large hip bones.

In adults, the hip bones are formed by the fusion of three pairs of bones: the ilium, ischium, and pubis. The pelvis joins together in the anterior of the body the pubic symphysis joint and with the bones of the sacrum at the posterior of the body. The Lower Limbs The lower limbs consists of the thigh, the leg, and the foot. The bones of the lower limb are the femur (thigh bone), patella (kneecap), tibia and fibula (bones of the leg), tarsals (bones of the ankle), and metatarsals and phalanges (bones of the foot) . The bones of the lower limbs are thicker and stronger than the bones of the upper limbs because of the need to support the entire weight of the body along with the resulting forces from locomotion. The lower limb consists of the thigh (femur), kneecap (patella), leg (tibia and fibula), ankle (tarsals), and foot (metatarsals and phalanges) bones. The femur, or thighbone, is the longest, heaviest, and strongest bone in the body.

The femur and pelvis form the hip joint at the proximal end. At the distal end, the femur, tibia, and patella form the knee joint. The patella, or kneecap, is a triangular bone that lies anterior to the knee joint; it is embedded in the tendon of the femoral extensors (quadriceps). It improves knee extension by reducing friction. The tibia, or shinbone, is a large bone of the leg that is located directly below the knee. The tibia articulates with the femur at its proximal end, with the fibula and the tarsal bones at its distal end. As the second largest bone in the human body it is responsible for transmitting the weight of the body from the femur to the foot. The fibula, or calf bone, parallels and articulates with the tibia. It is not weight-bearing, but acts as a site for muscle attachment while forming the lateral part of the ankle joint. The tarsals are the seven bones of the ankle, which transmits the weight of the body from the tibia and the fibula to the foot.

The metatarsals are the five bones of the foot, while the phalanges are the 14 bones of the toes .

Question: In the human body what name is given collectively to the five long bones of the foot?
Answer: Metatarsus